CFD Online Discussion Forums - Turbulent Boundary Conditions

hi all, i am new user of fluent and these i am doing a project to calculate CL,CD,CM over a general stepped(diameter is differnet at differnet locations) missile body at 2 degree AOA and M=2. Here i want to ask what is the correct method of specifying turbulent boundary conditions. I know there are 4 methods to specify them. What is the best method for my case??? how much they affect the accuracy of our results??? i went through the fluent manual and only came to know the method to specify Turbulent length scale i.e l=0.4*$($ is Bounday layer thickness) and Turbulent viscosity ration b/w 1-10. What is the best value for my case?? 1 or 10??? in what cases low values of turbulent viscosity ratio are better or when high values are better??? what is the method or formula to specify k and epsilon??? what is the method or formula to specify turbulence intensity???
Thanx in advance